New owner, need to do a few repairs... HELP PLEASE?

Hello... I JUST bought a 93 325i and need to replace a few parts. One is the alternator. I am a first time owner of a BMW and wonder how difficult it is to replace? And the steps required to do so...

Secondly, the previous owner had someone break into the trunk and the cylinder lock needs to be replaced. Contacted the dealership and am awaiting my cylinder lock to be shipped (laser key to match VIN). My question is... Is it simple to replace? I've replaced ignition cylinder locks before, and although it's a bit time consuming... I was able to do it myself, and I am a FEMALE! I do have a bit of technological savvy and a good mechanical aptituted.

Thanks for taking the time to read, and all who respond!